Rotronics RFC12

Thanks Allyn,

Thats one vote to Rotronics. looking forward to more replies

Allyn,
Just for interest sake, what isolator did you have before?

Cole Hersey and not worth a pinch of the proverbial

I have looked up the specs for the Redarc isolator. They do not give you any real specs and appear to be a high priced solenoid with a few electronics to give you remote control?? Hence the cheaper price. Forgive me if I am wrong. My guess is that if your starting battery is fine and your secondary is flat the flat battery is dumped in parallel with the good unit when using the Redarc. My understanding is that with the smarter units like Rotronics the charge of both batteries is sensed and the charge is switched individually between both batteries until both are charged up to a certain charge and then both batteries are charged in parallel. Perhaps Rod from Rotronics can confirm the operation of the unit. My Rotronics has served me well over the years. The first LC series 80 battery lasted 8 years (that was good luck)

Keith

Suggest you go back and read again the information on the Redarc website
The Redarc unit only charges the second battery when the main battery is charged
If you want to charge the second battery independently it is easily enough done with the Redarc unit. The electronic switch to do it is around $40 No real necessity in the majority of installations
With the number of faulty battery units that are replaced the basic functional units are reliable and work

Autolec,

You clearley have something against the Rotronic's units, and this may be justified. I don't know. But if the Rotronic's units are more complicated, then possibly they are more prone to failure. But if they actually do the job better, then there must be some consideration in using them if they have a good warranty. I am wondering why you have not sent some of these so called faulty units back to the manafacturer as Rod seems to be a very aproachable fella. Is it fair to can the product publically without at least letting him defend himself?

I am interested to hear more from any one else on the subject.

Autolec,

I am also keen to know how long after you installed these Rotronics units in your customer's vehicles that they failed and also under what conditions they failed. I would like to know for my own peace of mind, as from what I have read on this forum and also in many other places, the Rotronics units seem to have a much higher success rate, contrary to your claims.

I have had a GSL isolator fitted for 3 years now. Since fitting it I have never had to worry about it & it has performed very well. It is a cheaper option as I paid $109 from WES components ($120 now I believe). It is a parallel charge isolator so it does take a little longer to charge the aux battery as with all parallel systems. The problem is that most alternators these days are voltage sensed & when a fully charged main battery is paralled up to the Aux battery the alternator see's the voltage of the main fully charged battery and subsequently reduces its charge current. The way around this problem is to pay a bit extra and fit an independant charge system like the Rotronics RFC-12, as always it comes down to what your budget is. I went for a parallel system that cost under $300 including an Exide Extreme battery, works a treat but probably takes an hour or two longer to charge the Aux battery than an independant system. The GSL isolator uses relays rather than solenoid & will not switch in the Aux battery until the main is fully charged.
Cheers

I'm currently using a GSL also and they work by putting the AUX in parallel after main battery voltage is above about 13V, same as most isolators. Your comments about the alternator sensing the main battery volts as high and reducing the current are not quite right. Your main battery may be at 14.2V with the alternator running and yes it will not provide much current as it's fully charged but when you put the flat aux battery accross it the voltage will drop to somwhere in the middle of the flat and charged battery, so it may drop to 12V and the alternater will provide plenty of current. Get a volt and current meter and take some measurements. I can have a fully charged main bat and a flat aux and when the aux gets switched in I can measure it sucking in approx 50A and ther main taking about 2A.

Sam we have never fitted any Rotronics units. We have only replaced Rotronics units that customers have come in that have been faulty

We have replaced more Rotronics systems that all other brands combined

approx. how long after initial installation have the Rotronics units failed and under what conditions?

1st one was after approx 18 months and with little or no 4wding.
2nd one was in vehicle when I bought it so don't know how long it had been in but I only had the car four 6 months and it failed.

first rotronics box bleep after 9 mth replacement failed 3 mth then dealer fit a bosch box great

W.A. Police department and emergency services use the manual switch overs - nothing wrong with them - proves cheaper options work better!!Love the bush.
Chris

The Redarc units as you have found out are reliable.

The Piranha unit is just a GSL unit that is anodised red with a bit of cable on it and you will pay double the price for that privilege. The GSL battery isolator can be purchased for the same price as a Redarc

No units to my knowledge use "low tech Bi-metal circuit breakers".
The nut and bolt setup to connect the cables is preferential to having the cables directly connected

Autolec,
Hi, I'm not havin a go at you or your own thoughts on electrics, I am only asking you Questions here to gain knowledge.

# Can you please tell me what a "GSL" isolator is ??

# If " No units to my knowledge use "low tech Bi-metal circuit breakers", as you say, then are ALL units Electronic ??

My Piranha unit does have a three year waranty and is made of a sealed Black "bakerlite" type material, I was informed that the Nut & Bolt connections some times come loose & the crimping fails.

I have a GSL and have heard the piranha is the same but the GSL is in an aluminium heatsink type case (no idea why it is as there is nothing connected to the heatsink!)where as the piranha seem to be plastic and different shape, so I'm not sure they are the same. However the function of the 2 units is the same. I know piranha say their unit is fully electronic but I'm not so sure, my GSL unit is electronic but still relies on relays to switch the battery in. It's current limiting is electronic as in it doesn't rely on a bi metal strip as mentioned before. But for me to be totally electronic as Piranha claim I would think the switching would be done with transistors or Mosfets. Can someone confirm what the DBE150 uses to switch? My 150A GSL unit cost $110 where as the DBE150 I think is about $260 or higher depending on what model.

Also the cable as opposed to nut & bolt connector does seem like a good idea but I put some Locktight on the nuts to be sure and never had a problem

Piranha had a model that was identical to the GSL. I see it is now missing from their website.

Andy looks like you have studied the Piranha website quoting it verbatim. Are you a Piranha sales person or a commission agent.

If you are the least bit handy you could build the MOSFET kit from DSE or Jaycar for $49.93

For the GSL unit www.gsl.com.au/products/ebi.shtml

Nigel,

You say you are impressed with how quickly the system charges the deep cycle. Is this compared to another system you have had?
I currently have an Arrid system, but have been told that the Rotronics will charge alot faster. Everything I have read seems to tell me this is the case.
Any feed back would be much appreciated.

cheers

Andy

I have not had any other systems, but had been told to expect a deep cycle to take quite a few hours to recharge. I find I only need to drive for 1 or 2 hours a day to keep everything running smoothly.

The rotronics system like mine (and I think there is one other brand) is designed to charge either the starter battery OR the aux, so each battery gets the full alternator charge in turn. Normal systems charge the main battery, then bring the aux in parallel with the main so the alternator is charge a half flat aux and a full main at the same time.

With deep cycles the type of battery plays a part in recharge time too. If you can get a deep cycle that also has a high CCA then it will have lower internal resistance and will therefore accept charge quicker. My 90 Ah Federal (got it at battery world) has a CCA of 575 which makes it an ideal 4WD aux as it could start my vehicle if my main battery died.

Nigel,

thanks for the feed back

regards

Andy